For decades, the Abu Sayyaf Group (ASG) has been considered the most notorious bandit organisation in Southeast Asia.

It carried out the biggest act of terrorism in the country when it bombed a ferry in 2004, killing more than 100 people. But the recent video clearly shows a whole new level of brutality not seen in the Philippines in recent years.

Filipino soldiers carry a recovered body in the town of Jolo, Sulu island in April 2016 [EPA]

Beheading is one of the most obscenely brutal ways of executing someone - even more so when it is not done in one fell swoop of a sword, but with slashes and hacks from a hunting knife.

This atrocity happened recently in Sulu, a southern backwater island province in the Philippines. It has gained notoriety in Southeast Asia's "kidnapping capital", a jungle terrain where the Abu Sayyaf is known to operate.

For such a scenic place, its reputation is one of the darkest in the world.

About 70 percent of the population in Sulu is poor, according to the latest government census. Many children are out of school, roads and bridges remain unfinished, and medical facilities and clean water are virtually non-existent.

Jobs are hard to come by. Most of the food available in Sulu is shipped in from its more affluent neighbour Zamboanga City, or from Sabah in eastern Malaysia. Developing Sulu's agriculture industry is difficult, despite its fertile soil.

People are unable to till their land out of fear. Others say their farmland and homesteads have been taken forcibly from them and occupied by armed groups such as Abu Sayyaf.

It is the perfect petri dish in which to grow a secession, a place long held back by four decades of armed conflict and government neglect, yet one with a population that continues to grow and need.

To the rest of the country - and the world - Sulu is like a black hole. For most Filipinos, the word "Sulu" is synonymous with "terrorism". The place only makes global headlines when hostage-beheading videos go viral.

Abu Sayyaf was born more than a decade and a half ago in Basilan, one of the most impoverished provinces in the southern Philippines. Its name literally means "bearer of the sword".

Its founder, Abubakar Abdurajak Janjalani at first sought to create a separate Islamic state for the Muslim minority. He was killed in a military operation. Its co-founder Radulan Sahiron is still one of the most-wanted men in the country. He was once a member of the secessionist Moro National Liberation Front, which has since brokered peace with the government.

Abu Sayyaf started ideologically but shifted to criminal activities a few years after to sustain itself.

The group has engaged in countless kidnappings for ransom, attacks, and even drugs and weapons smuggling.

The Philippine military puts the number of Abu Sayyaf fighters at about 400, but they triple in numbers when hostages are taken.

'Jihad'

Abu Sayyaf is a loose organisation. There is no single, unifying force of leadership. There are several Abu Sayyaf factions spread across different territories in the Sulu archipelago.

Yet, it is quite disciplined financially and militarily. Most of its money goes to weapons purchases. It doesn't buy gold or build expensive homes within the provinces, according to Philippine military intelligence sources.

Atrocities committed are part of their "jihad", leaders say, but the apparent motivation is about money through "terror" activities.

Abu Sayyaf's main motivation is to create a state of terror in the areas it controls.The rise of Islamic State of Iraq and the Levant (ISIL) in the Middle East has helped fuel Abu Sayyaf violence.

The beheading broadcast over YouTube has helped spread propaganda through easily available handheld phones.

According to military sources, some members of Abu Sayyaf are as young as 15. These teenagers are born impoverished - mostly orphaned by rebels - and have never had the chance to go to school.

In Sulu, these boys are called Anak Itu - or orphans of war.

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For many of those recruited, it is all about identity and a sense of belonging. They have lived all their lives under siege. In Sulu, long forgotten by the national government, so many young people say they feel left out. They say they are judged for being Moro, judged for being poor. Then comes a group that gives them weapons and a sense of community. It's a warped version of reality.

However perverted it may seem, it is the only irresistible draw in an otherwise bleak existence.

It is the only life they know.

Blood, money, and narcotics

How does Abu Sayyaf maintain its influence? Ties of blood and money - with a dash of political convenience to keep operations running smoothly.

The group buys a lot of weapons - millions of dollars' worth. Military reports show multimillion-dollar procurements shortly after every ransom pay-out.

A classified document seen by Al Jazeera also reveals Abu Sayyaf members went on a shopping spree for weapons shortly after their release of 14 Indonesian hostages a few weeks ago. Ransom is paid, which means more money to expand operations.

Military sources, who spoke on condition of anonymity because they were not authorised to go on record, say Abu Sayyaf buys weapons and ammunition from local government officials, smuggled mostly from nearby countries.

On lean days, when they have no hostages and ransom to collect, military intelligence officers say Abu Sayyaf's members work closely with local politicians and police who are blood relatives.

Abu Sayyaf has also been buying tracts of land to expand its territory.

An impoverished farmer, marginalised and intimidated by armed groups, is an easy target. Often poor families are forced to sell their land to the group.

Bud Pula, or Red Mountain, in Patikul has some of the most rugged terrain in the Sulu archipelago. This is where most hostages are hidden, according to army sources.

Another approach the group uses to gain influence is through clan ties. Military officials say that intermarriage is a strategy.

Abu Sayyaf factions are composed mostly of their own family members. They intermarry to solidify their connections. It is not unusual for a widow of an Abu Sayyaf member to be pressured by relatives to marry another fighter to keep their affinities strong. It is also easier to recruit new members through clan ties.

By paying dowries, they are able to buy loyalty from the families into which they marry and expand their influence. Looking at the Abu Sayyaf's connections in Sulu is like looking at several intertwined family trees.

The families that compose the group are in connivance and, in that sense, they are stronger. This is how they have survived.

This has made it difficult for the intelligence community to penetrate the group. It is almost impossible for any outsider to be part of the inner circle of the Abu Sayyaf.

The policy of leader Radullan Sahiron is to never allow outsiders into his immediate circle. This is how he has remained in hiding for more than 15 years. He, too, is protected by his family members. There are practically zero outsiders. Once a member leaves camp, the rule is simple - he cannot come back.

Urban allies

But leaving the hinterlands does not mean a member is no longer useful to the group.

The member can still maintain alliances as part of Abu Sayyaf's urban force.These are members who live and work in nearby towns with their families.

They serve as "sparrows", or urban spies, mostly monitoring the military's movements.

They help procure and deliver ammunition and even spot potential kidnap-for-ransom victims as far as Sabah in eastern Malaysia and in the Celebes Sea, close to the border of Indonesia.

The "urban" membership has expanded, which is why Abu Sayyaf has also lately been able to conduct more abductions by broadening their operations as far as Palawan on the western front, the Davao Gulf, and as far as Malaysia's Sabah.

The proliferation of narcotics is a daunting problem, too.

According to the Philippine military, the much younger members of the group are usually supplied with methampethamine hydrochloride - commonly called "shabu" or crystal meth. They are given the drugs days before they are sent to the frontlines to fight the Philippine military.

In an interview with Al Jazeera last year, the late Colonel Paolo Perez of the Philippine Army, who commanded a battalion in Basilan, said: "The youngest ASG [Abu Sayyaf] member we captured while fighting in the frontlines was only 14. He was like a bull when he was fighting but when he was wounded, he started crying. The next day, he couldn't remember what he did. He admitted he was given drugs before fighting - he was just a boy really."

How is the Abu Sayyaf able to do all this? Not without support of local government officials, military officials say.

Cocoy Tulawie, a politician and member of an influential family in Sulu, said this has long been the norm and local government officials have been in connivance with Abu Sayyaf for decades.

He said younger members are ignorant of Islam, yet they are extremely fanatical about representing it. Their version of Islam is flawed simply because the dawas - or Islamic schools - are usually in the main towns and they do not get the chance to study the Quran "properly".

That ignorance, he said, is what makes them dangerous.

Tulawie also criticised religious leaders in Sulu for not speaking out against Abu Sayyaf's actions, noting that no one has condemned the violence as anti-Islam.

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"Local politicians lack the political will," Tulawie said. "The priority is money and to maintain power. It is not their priority to run after the ASG, because they do not want to be seen as the enemy of the ASG. And because local politicians, just like Abu Sayyaf, share the same interests. They are also involved arms dealing and weapons smuggling of drugs and food from Sabah, Malaysia and other neighbouring countries.

"Newly elected President Rodrigo Duterte must realise that if he wants to fix the problems of Sulu, he has to isolate the local politicians. He needs to see that those government officials must be put under investigation," Tulawie said.

"The president will have to work directly with military and police forces based outside Sulu, because police officers there have been corrupted. Duterte cannot allow himself to be befriended by Sulu's local politicians, because those same politicians are part of the problem. They must be investigated for their involvement in drug smugglings and corruption."

He alleged some local officials have taken shares of ransom money from hostage-taking for decades. It is a multimillion-dollar industry, he added, that has been profiting from the chaos and violence in Sulu.

Newly appointed Armed Forces Chief Ricardo Visaya also said he believes local government officials in Sulu have been involved in kidnap-for-ransom operations. "Governors, vice-governors, down to village chiefs," he said in a recent interview with a local journalist.

"The ARMM [military] headquarters, located in central Mindanao, did not prioritise the Sulu archipelago, and money intended for development rarely reached this island," the report said.

"To get aid and money, local politicians there allowed the ASG to engage in infractions with the expectation that they would receive resources that they could exploit for political reasons."

Military successes and failures

Philippine special forces are seen to be the most proficient of all Southeast Asian commandos, especially when it comes to counter-insurgency operations.

The Philippine military has been fighting various rebel groups in Sulu for decades.

The Sulu problem is complex - and one that requires political will and a long-term strategy. President Duterte has said he is contemplating putting the entire Sulu archipelago under martial law - an approach supported by a majority of those in the military's top brass.

But not everyone agrees.

Retired Brigadier-General Juancho Sabban, who spent five years in Jolo trying to contain the threat, said bombing communities is not the solution.

"Right now the communities are no longer cooperative. In any insurgency ... the centre of gravity is the people. When you get the people on your side, you win the war. But over the last few years, the leadership of the military thinks that only military operation is the right solution," Sabban told Al Jazeera.

One way to get people onside is to address their needs and grievances, he added. Doing that will help deny the enemy the logistics and support it needs.

"We had only about 20 percent military operation, and those were intelligence-driven combat operations - which is the key to a successful operational intelligence. If you keep doing combat operations with flawed intelligence, you are not only able to achieve your target, you are also endangering the lives of your men, because you are exposed and they don't know who the enemy is," Sabban said.

"If you look at the casualty rate now compared to the period of 2006-2010, there were a lot of encounters that were initiated by government forces. While recently, it is now the Abu Sayyaf leading the offensive against us. We had a policy then - find them, fix them, finish them."

Philippine military spokesman General Restituto Padilla said there has been no degradation when it comes to providing social services from the military. "Kidnap-for-ransom earnings that pour into communities are so much bigger lately that people tend to gravitate towards the ASG. That's a hard reality on the ground.

"Eliminating the Abu Sayyaf within a year is doable for us. But the military will need the support from local and government officials. What is needed here is political will."

An entire generation has already been born into armed conflict since the Philippine government started its offensive against the Abu Sayyaf decades ago.

Residents of Sulu say they cannot remember a single day without fighting erupting in their communities.

Sulu has seen some of the most horrific atrocities committed against civilians that go back as far as the 1970s, when martial law was implemented during the time of then president Ferdinand Marcos. There has been no let-up in violence since. People are war-weary.

The land of Sulu is soaked in the blood of both the oppressor and the oppressed.